The SeaWinds on ADEOS-II Level 3 ocean vector winds on a 0.25 degree grid contains daily data from ascending and descending passes; where adjacent satellite passes overlap, the most recent value overwrites the previous value for that particular wind vector cell. Wind vectors are accurate to within 2 m/s (vector speed) and 20 degrees (vector direction). Rain flags are provided for each wind vector cell to assist in identifying potential rain contamination. Wind vectors are set to a value of 0 when within 30 km of land/ice boundaries or where there is ambiguous or non-existent measurements available. This data utilizes the recalibrated model function called the QSCAT-1/F13 processing algorithm, adopted in July of 2006.

SENSORName: SeaWinds Scatterometer (SEAWINDS)Swath Width: 1800 kmDescription: SeaWinds is a Ku-band (13.4 GHz) Scatterometer which features a single circular scanning dish antenna to provide pencil-beam measurements, as opposed to the common fan beam design as seen with other spaceborne scatterometers. The pencil-beam design has several key advantages over the more common fan beam design: higher signal-to-noise ratio, smaller size, and superior coverage. The SeaWinds single antenna utilizes twin offset feeds, thus providing two pencil-beam footprint paths with an elliptical sampling footprint of approximately 25 km (in azimuth) by 37 km (in look/range direction); these pencil beams have opposing polarizations (i.e., vertical and horizontal), thus achieving dual-polarization. The SeaWinds instrument provides a full 1800 km-wide swath coverage (including the nadir region), which allows for a nominal daily measurement coverage of 90% over the ice-free oceans.